Since most IPv4 transfers so far have occurred as private transactions the price for the address blocks has generally not been known. There are various economic methods and theories which could predict the value of the underlying IPv4 address rights, but those models may not bear much resemblance to the actual market due to the model’s inability to take into account all the factors effecting the IPv4 marketplace.
There are a few public exceptions to the pricing data, notably bankruptcy cases (Nortel @ $11.25/address & Borders @ $12/address) where the pricing was made public as a part of the court filings.
Hilco Streambank which is an ARIN registered transfer facilitator has started a new auction service which is openly posting pricing for the IPv4 blocks. According to their website, six blocks ranging in size from a /17 to a /24 have been sold in the past couple of months through this site. (Their site reports the auctions have closed, but the actual transfer may not have occurred.) (copy)
Looking at the pricing information that they have posted, there is a clear premium being paid currently for smaller blocks. The /24 block sold for $ 6,225 or $24.31 per address whereas the larger /17 & /20 blocks sold for between $7.25 – $7.32. The actual bid information is not released publicly on their site, so we do not know how many organizations were bidding for the blocks or if the blocks sold for the minimum listed price.
It will be interesting to continue to watch to see how pricing for blocks changes over time and if other trends develop based upon source or destination RIR region for the transfers.
Links to sites on IPv4 pricing models and theories: